Techniques for wireless communication of proximity based content

ABSTRACT

A system and method for close proximity communication is disclosed. The method comprises detecting a signal transmitted by a close proximity communication (CPC) device at a distance of one of greater than and less than a CPC detection perimeter with a multi-mode magnetic induction communication (MMMIC) device having at least one antenna. The type of device transmitting the detected signal is identified. The MMMIC device is enabled to communicate with the close proximity communication device at one of the distance of greater than the CPC detection perimeter and less than the CPC detection perimeter based on the type of device that is identified.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of a U.S.Provisional application filed on Mar. 22, 2010 in the U.S. Patent andTrademark Office and assigned Ser. No. 61/466,448, the entire disclosureof which is hereby incorporated by reference.

BACKGROUND

A significant expansion in mobile computing devices and wirelesscommunication has occurred in the early 21^(st) century. The use ofmobile computing devices is often an every day occurrence for manypeople. With the expansion has come a consolidation of electronic andevery day devices. For instance, a typical smart phone now includes manyfunctions that previously required the use of several separate products,such as a phone, a camera, a planner, a video player, a video gamedevice, a planner and so forth.

The consolidation of functions in mobile computing devices iscontinuing. One function that is becoming widely adopted is the use ofwireless communications from a mobile computing device to replace theuse of credit cards. Rather than having to swipe a credit card to conveythe necessary information to complete a financial transaction, acustomer can use his or her smart phone to transmit credit cardinformation or other financial information needed to complete thefinancial transaction.

One wireless technology that is facilitating the use of mobile computingdevices to conduct financial transactions is the use of Near FieldCommunications (NFC). NFC is a simple extension of the InternationalOrganization for Standards (ISO) 14443 proximity card standard. Wirelessdevices using the standard can communicate with smart card readerswithin a 10 centimeter (four inch) radius. Thus, a smart phone that isNFC compliant can communicate with an electronic store transactiondevice to complete a transaction when the phone is placed within aboutfour inches of the transaction device. By minimizing the radius in whichcommunication can occur, the security of the transaction issignificantly increased. However, the relatively small radius in whichdevices operating on the ISO 14443 standard can communicatesignificantly reduces the usefulness of the standard beyond closeproximity communications.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the invention will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the invention; and, wherein:

FIG. 1 illustrates a block diagram of an NFMI device in communicationwith an NFC compliant device at a selected distance in accordance withan embodiment of the present invention;

FIG. 2 illustrates a block diagram of a mobile computing devicecontaining an NFMI device configured to communicate with an NFCcompliant device at a selected distance and other NFMI devices inaccordance with an alternative embodiment of the present invention; and

FIG. 3 depicts a flow chart of a method for close proximitycommunication in accordance with an embodiment of the present invention.

Reference will now be made to the exemplary embodiments illustrated, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION

Before the present invention is disclosed and described, it is to beunderstood that this invention is not limited to the particularstructures, process steps, or materials disclosed herein, but isextended to equivalents thereof as would be recognized by thoseordinarily skilled in the relevant arts. It should also be understoodthat terminology employed herein is used for the purpose of describingparticular embodiments only and is not intended to be limiting.

It should be understood that many of the functional units described inthis specification have been labeled as modules, in order to moreparticularly emphasize their implementation independence. For example, amodule may be implemented as a hardware circuit comprising custom VLSIcircuits or gate arrays, off-the-shelf semiconductors such as logicchips, transistors, or other discrete components. A module may also beimplemented in programmable hardware devices such as field programmablegate arrays, programmable array logic, programmable logic devices or thelike.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions, which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.The modules may be passive or active, including agents operable toperform desired functions.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, appearancesof the phrases “in one embodiment” or “in an embodiment” in variousplaces throughout this specification are not necessarily all referringto the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various embodiments and example of the presentinvention may be referred to herein along with alternatives for thevarious components thereof. It is understood that such embodiments,examples, and alternatives are not to be construed as defactoequivalents of one another, but are to be considered as separate andautonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of materials, fasteners, sizes, lengths, widths, shapes, etc.,to provide a thorough understanding of embodiments of the invention. Oneskilled in the relevant art will recognize, however, that the inventioncan be practiced without one or more of the specific details, or withother methods, components, materials, etc. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

Definitions

As used herein, the term “substantially” refers to the complete ornearly complete extent or degree of an action, characteristic, property,state, structure, item, or result. For example, an object that is“substantially” enclosed would mean that the object is either completelyenclosed or nearly completely enclosed. The exact allowable degree ofdeviation from absolute completeness may in some cases depend on thespecific context. However, generally speaking the nearness of completionwill be so as to have the same overall result as if absolute and totalcompletion were obtained. The use of “substantially” is equallyapplicable when used in a negative connotation to refer to the completeor near complete lack of an action, characteristic, property, state,structure, item, or result.

As used herein, the term “about” is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint.

As used herein, the term “mobile computing device” refers to a deviceincluding a digital processor coupled to a digital memory. The mobilecomputing device may be a simple device operable to receive a signal andrespond. Alternatively, the mobile computing device can be a complexdevice having multiple processors and a display screen.

As used herein, the term “NFC compliant device” refers to a wirelesscommunication device that is compliant with at least one of the ISOspecifications including ISO 14443A, ISO 14443B, ISO 18092, and ISO15693. At the time of writing, the most current ISO 14443 specificationfor parts A and B consists of four parts: (1) the ISO/IEC 14443-1:2008disclosing physical characteristics specifications; (2) the ISO/IEC14443-2:2001 disclosing radio frequency and signal interferencespecifications; (3) the ISO/IEC 14443-3:2001 disclosing initializationand anti-collision specifications; and (4) the ISO/IEC 14443-4:2001disclosing transmission protocol specifications. The ISO 15693specification consists of three parts: (1) ISO/IEC 15693-1:2000disclosing physical characteristics specifications; (2) ISO/IEC15693-2:2006 disclosing air interface and initialization specifications;and (3) ISO/IEC 15693-3:2009 disclosing anti-collision and transmissionprotocol specifications. An NFC compliant device is considered to becompliant if the device is substantially compliant, or expected to besubstantially compliant with an accepted version of the ISO 14443, ISO18092, or ISO 15693 specifications, whether the accepted date isprevious to the versions listed above or consists of a future acceptedversion of the specifications, or has evolved from similar technologyover time. The term NFC compliant device can also refer to other typesof close proximity communication devices that are not compliant with theISO 14443 specifications but are configured to communicate over of adistance of less than about 10 cm.

As used herein, the term “close proximity communication” or “CPC” refersto a close proximity communication transmitted and/or received by aclose proximity communication device within a close proximity of anotherdevice configured to communicate with a CPC device, such as, forexample, over a distance of less than about 100 cm, less than about 50cm, less than about 30 cm, less than about 20 cm, less than about 10 cm,or less than about 5 cm.

As used herein, the term “close proximity communication device” or “CPCdevice” is intended to refer to NFC compliant devices, as well as othertypes of devices that are configured to communicate only within a closeproximity, such as within a proximity of less than about 100 cm, lessthan about 50 cm, less than about 30 cm, less than about 20 cm, lessthan about 10 cm, or less than about 5 cm, for example.

The term “CPC detection perimeter” or “CPC perimeter” refers to aperimeter or boundary of a range of detection for a close proximitycommunication, such as a distance of less than about 100 cm, less thanabout 50 cm, less than about 30 cm, less than about 20 cm, less thanabout 10 cm, or less than about 5 cm. The CPC perimeter is notnecessarily symmetrical. The CPC perimeter may be based on the physicalparameters of a CPC device, such as antenna size, power output, receivesensitivity, and so forth. In a specific example, the CPC perimeterrefers to a range in which a close proximity communication signal has asignal strength above a predetermined level as detected by an antenna ofa CPC device. Alternatively, the CPC perimeter may refer to a selecteddistance over which a standard is defined to communicate. For example,the CPC detection perimeter of two NFC devices in communication isapproximately 10 cm.

Example Embodiments

An initial overview of technology embodiments is provided below and thenspecific technology embodiments are described in further detail later.This initial summary is intended to aid readers in understanding thetechnology more quickly but is not intended to identify key features oressential features of the technology nor is it intended to limit thescope of the claimed subject matter.

Near Field Communication (NFC) enables the exchange of data betweendevices over a CPC perimeter of about a 10 centimeters (around 4 inches)distance. The technology is a simple extension of the ISO/IEC 14443proximity-card standard (proximity card, RFID) that combines theinterface of a smartcard and a reader into a single device. An NFCdevice can communicate with both existing ISO/IEC 14443 smartcards andreaders, as well as with other NFC devices, and is thereby compatiblewith existing contactless infrastructure already in use for publictransportation and payment.

As the acceptance and use of mobile computing devices increases, thefunctionality of these devices continues to expand. Applications formobile computing devices may include access control. For example, usinga Smartphone or other type of mobile computing device as a replacementfor car keys, door keys, or login security to a computer or otherdevices that require access control. Currently Passive Keyless Entry(PKE) is a stand-alone functionality contained in a key fob, but may beintegrated into a mobile computing device.

Another application is a proximity based exchange of information over apersonal area network. A personal area network may comprise a distanceof up to about 2 meters from the user. The ability to exchange data atdistances greater than the NFC (up to about 10 cm) specification allows,and yet more localized than current Bluetooth (up to about 10 m)specifications provide, is becoming increasingly more in demand as moreand more people are carrying and utilizing mobile computing devices.Such exchange of information may be the transfer of data between amobile computing device and a computer, or peer to peer, such asbusiness card information exchange, product catalogs, URL address,product solicitation, marketing material, or social networkinginformation such as personal profiles, calendars, social status, orproximity detection of other users within the same social network.

As wireless usage increases through an increase in wireless applicationsand an increase in the number of wireless users, there is a greater needfor more localized, short-range wireless communication capabilities suchas magnetic induction communication in order to minimize spectrumcontention and ensure a good quality of service for each user. The needfor more localized, short-range wireless communication capabilities isespecially true in congested areas like shopping malls, stores, sportingevents, conventions, restaurants, schools, the workplace, or otherpublic gathering places.

A current challenge or difficulty to provide different applications thathave multiple ranges of wireless communication is that each type ofapplication described may require a unique or separate wirelesscommunication system. The hardware required to meet the physical layerspecifications of each system varies; and currently these systems areseparate, discrete systems requiring separate antenna arrays, filters,low noise amplifiers (LNAs), power amplifiers (PAs), modulation anddemodulation hardware, memory, and so forth. This complexity oftenrequires additional electronic real estate inside of a device, therebymaking it bulky and therefore impractical to employ all of the variousshort range magnetic induction capabilities in one device, such as aSmartphone or mobile computing device.

The relatively short communication range or CPC perimeter ofapproximately 10 centimeters (4 inches) for NFC compliant devices isconvenient for security purposes since signals transmitted by the NFCdevice will typically not be received by other NFC compliant devicesthat are further than about 10 cm away. However, the relatively shortrange significantly reduces the usefulness of near field communications.

The signals transmitted by NFC compliant devices typically cannot bereceived by other NFC compliant devices outside of an approximately 10cm radius due to inherent limitations placed in the ISO 1443specification. For example, the specification provides for the use ofonly a single antenna. Signals that are transmitted using near fieldcommunications rely on magnetic induction. The magnetic induction signalis optimally received by an antenna that is parallel to the inductionsignal (i.e. parallel to the transmitting antenna). When the transmitantenna and the receive antenna are in an orthogonal plane relative toeach other then the signal received has a minimum power. When twodevices are relatively close, such as the 10 cm maximum range prescribedin the ISO 1443 specification, then the angular displacement between thetwo antennas is not as important. Particularly if the distance betweenthe transmitter and receiver is small relative to the diameter of thetransmitter antenna coil. However, as the distance between thetransmitter and receiver increases, compared to the diameter of thetransmitter coil, the angular displacement between the receiver and thetransmitter antennas becomes increasingly important.

One technique for increasing the distance at which a device can receivea signal transmitted by a near field communication compliant device isthrough the use of multiple antennas that are mutually orthogonal to oneanother. The use of multiple orthogonal antennas to receive a magneticinduction modulated signal will be referred to as magnetic inductiondiversity. In one embodiment, the use of magnetic induction diversitycan be used in combination with spatial diversity to allow the benefitsof both spatial diversity and magnetic induction diversity to beaccomplished.

Magnetic induction diversity can be the selection of the best alignedantenna to receive or transmit with another transceiver. Alternatively,magnetic induction diversity can involve summing the signal on two ormore antennas. The use of magnetic induction diversity enables thevariability of the proximity boundary to be substantially reduced.Since, in a system with multiple receiver antennas positioned inorthogonal planes, a receive antenna can always be selected that issignificantly aligned (i.e., parallel) with a transmit antenna, itreduces the need to significantly increase the transmit power to ensurethat the signal can be received at a selected distance independent ofits relative orientation with the transmit antenna, and vice versa. Itshould be noted that the use of NFC transceivers does not, by itself,constitute magnetic induction diversity. The distance over which amagnetic induction device can communicate (i.e. a range) when usingmultiple orthogonal antennas to provide magnetic induction diversity candepend on a number of factors, including but not limited to acommunication range of a transmitter and a receive sensitivity of areceiver. A number of additional factors can also contribute includingthe degree of orthogonality, the number of transmit and receiveantennas, the shape and size of the antennas, the transmitter outputpower, the efficiency of the receiver, and so forth.

Through the use of magnetic induction diversity, wherein one or moreantennas are selected from the multiple antennas based on their abilityto receive or transmit a signal, the use of multiple antennas cansignificantly improve the ability to detect a signal transmitted by anNFC compliant device by ensuring optimal inductive coupling bymaintaining the most efficient angular displacement between the transmitand receive antenna. In one embodiment, the signal detected by each ofthe orthogonal antennas can be summed to provide a maximum strengthdetected signal, thereby maximizing the distance over which the signalcan be detected. Alternatively, a selection metric of the receivedsignal can be measured at each antenna and one or more antennas can beselected for use in transmitting and/or receiving based on the selectionmetric. In addition, the transmitting signal can be sent over multipleantennas in an effort to target more energy to an NFC device's receiveantenna(s).

For example, FIG. 1 provides an example illustration of a near fieldmagnetic induction (NFMI) device 102 having three mutually orthogonalantennas 104, 106 and 108 that are located in the X, Y, and Z axesrespectively. The NFMI device is separated from an NFC compliant device110 by a distance 114. When the separation distance is greater than 10centimeters (cm) then other NFC compliant devices typically cannot readthe signal transmitted by the NFC compliant device.

In accordance with one embodiment of the present invention, magneticinduction diversity can be used to increase the distance 114 over whicha signal can be received. The increase in distance can come without asignificant increase in transmission power or electromagnetic emissions,which can cause mutual interference in other similar devices and orviolate FCC limits and/or regulations. A signal transmitted by an NFCcompliant device 110, or another type of magnetic inductioncommunication device, can be detected through the use of at least twoorthogonal antennas.

In one embodiment, the signal detected by each of the orthogonalantennas can be summed to provide a maximum strength detected signal.Alternatively, a selection metric of the received signal can be measuredat each antenna. Some examples of selection metrics that may be used toselect an antenna to receive the signal are listed below:

-   -   receive Signal Strength Indicator (RSSI), wherein the antenna        having the greatest RSSI is selected to receive the signal;    -   decoder output bit error rate (BER), wherein the antenna with        the received signal having the lowest BER at the decoder is        selected to receive the signal;    -   round-robin strategy (i.e. try each possible selection in turn        and choose the best); and    -   Shannon capacity, wherein the antenna providing a received        signal with the highest Shannon capacity or highest        instantaneous link capacity is selected.

Additional techniques can also be used as a selection metric, such asEigen value selection of an antenna and selection based on the detectionof cyclic redundancy codes used with forward error correction.

Moreover, the signals of multiple antennas can be selected and summed.Summing the receive signal on the multiple antennas enables a relativelylow power signal, such as a signal transmitted by an NFC compliantdevice, to be received with a greater efficiency than is typicallypossible with a single antenna, thereby enabling the low power signal tobe received at a greater distance than is possible with a device using asingle antenna. Summing the receive signal can be accomplished invarious ways. For example, in one embodiment, the receive signal on eachantenna can be summed. In another embodiment, the best two antennas canbe selected and summed based on the selection metrics. Any metriccapable of prioritizing the antennas based on the received and/ortransmitted signals between at least two magnetic inductioncommunication devices is considered to be within the scope of thepresent invention.

In one embodiment, the near field magnetic induction device 102 can beconfigured to change modes based on a distance 114 from another nearfield communication device 110. A mode, as used herein, is a specificmagnetic induction diversity scheme, a selected modulation scheme, apower output scheme, or some combination of these schemes based ondesired operation and/or specification requirements. The use of aspecific magnetic induction diversity scheme and modulation scheme canalso affect the power output, the frequency of the signal, and thereceive sensitivity, among other variables, as can be appreciated.

A device that is configured to change modes to communicate over aselected distance is referred to as a multi-mode magnetic inductioncommunication (MMMIC) device. For instance, when the MMMIC device 102 iswithin a distance 114 of an NFC compliant device 110 then it can switchto an NFC compliant mode. When the MMMIC device is at a distance 114 ofgreater than about 10 cm (i.e., the CPC perimeter), then the MMMICdevice 102 can switch to a mode incorporating the use of magneticinduction diversity to increase transmit power and receive signalsensitivity of the MMMIC device 102 with the NFC compliant device 110,thereby enabling communication at a distance 114 of greater than the CPCperimeter. The different modes may require different modulation schemes,power output levels, carrier frequency and so forth. This will bediscussed more fully in the proceeding paragraphs.

There can be at least three different modes of communication for a MMMICdevice: 1) a long range to long range mode (such as, for example, aMMMIC device communicating with an NFMI device); 2) a short range toshort range mode (such as, for example, the MMMIC device in NFC modecommunicating to an NFC device); and 3) a hybrid mode (such as, forexample, where the MMMIC device can detect and communicate with an NFCdevice while outside the CPC perimeter. The MMMIC device can function asan extended range communication device (such as up to 2 meters or more,for example) and/or a short range NFC-type device or both.

At least two of the antennas 104-108 of the MMMIC device 102 with thedesired selection metric, can be selected as the receive antenna toprovide magnetic induction diversity. Antenna selection may be performedat a regular rate, such as several times per second. Antenna selectionmay be performed as often as every data packet that is received at theNFMI device 102. As each packet is received, the antenna(s) having thedesired metric can be selected. Thus, as a mobile NFMI device is movedand rotated, the antenna(s) that are most closely parallel to thetransmit antenna in the NFC compliant device, or with the greatestSignal-to-Noise Ratio (SNR), can be used to receive the signaltransmitted from an NFC compliant device.

In one embodiment, the at least two antennas 104-108 in the MMMIC device102 can both be used to transmit and receive with the antenna in the NFCcompliant device 110. As communication between the devices occurs, thedesired metric can be used to identify at least one of the antennas104-108 in the MMMIC device that is most closely parallel with theantenna in the NFC compliant device 110. This allows the MMMIC device102 to be moved and rotated with any type of angular displacementrelative to the NFC compliant device 110 without significantly reducingthe power of the received signal, thereby enabling the MMMIC device tocommunicate with the NFC compliant device at greater distances than astandard NFC compliant device having a single antenna would allow, whilerequiring no increase in the transmit power signal at the NFC compliantdevice.

In addition, the MMMIC device 102 may include features that furtherincrease the ability of the MMMIC device to receive the relatively lowpower signal transmitted by the NFC compliant device. For example, oneor more of the plurality of antennas 104-108 in the MMMIC device may belarger than the antenna design disclosed in the ISO 14443 specification.The ISO 14443 specification requires that a compliant antenna consist ofa proximity integrated circuit card (PICC) antenna having dimensions ofless than 81 milimeters (mm) by 49 mm.

The MMMIC device 102 can include larger antennas, or antennas having nonplanar shapes that are designed to have an increased gain relative tothe PICC antenna disclosed in the ISO 14443 specification. The increasedgain of the antenna(s) in the MMMIC device enables receive signals to bedetected that have a lower power than can be received with an ISO 14443compliant PICC antenna.

Antennas in the MMMIC device 102 can be selected based on the mode ofthe MMMIC device. For instance, if the MMMIC device is in an NFCcompliant mode, a single antenna that is compliant with the ISO 14443specification may be selected to transmit and receive with the NFCcompliant device 110. Alternatively, if the MMMIC device is located adistance 114 of greater than 10 cm from the NFC compliant device, orautomatically or actively changed to operate in a non-NFC compliantmode, then the MMMIC device may use magnetic induction diversity,wherein one or more antennas 104-108 that are not compliant with the ISO14443 specification may be used to allow the MMMIC device to communicate(transmit and/or receive) with the NFC compliant device at a distancegreater than the CPC perimeter of 10 cm.

Additional components comprising the radio frequency (RF) front end ofthe MMMIC device 102 may also be selected to be more sensitive thanthose used in an NFC compliant device 110. For example, a low noiseamplifier (LNA) in the MMMIC device may have a lower noise figure thanthe LNA used in an NFC compliant device. In another example, a ferriteloaded core antenna or specialized materials selected in the antennamaterials may be used to increase transmit and or receive efficiency ofthe MMMIC device.

In one embodiment, the NFMI device 102 can be a dual mode or amulti-mode device configured with the ability to change communicationprotocols to communicate with multiple inductively coupled communicationdevices having different communication protocols. For instance, theMMMIC device 102 can be configured to communicate with another MMMICdevice using Gaussian minimum shift keying (GMSK), Quadrature PhaseShift Keying (QPSK), or another suitable modulation scheme at a carrierwave frequency of F₁.

NFC compliant devices are typically configured to use amplitude shiftkeying (ASK) modulation on a carrier wave frequency of F₂, which istypically 13.56 Megahertz (MHz). The frequency F₁ may be the same as, ordifferent from F₂ depending on the type of application for which theNFMI device is applied.

For instance, in one embodiment the MMMIC device 102 may be incorporatedin a cell phone, laptop, tablet computing device, handheld computingdevice, or other type of mobile computing device 202, as shown in FIG.2. While the mobile computing device is described herein as beingmobile, the mobile computing device may be a fixed device. The mobilecomputing device can be a handheld computing device, a portablemultimedia device, a smart phone, a tablet computing device, a laptopcomputer, an embedded computing device or similar device. An embeddedcomputing device is a computing device that is inlayed in a selectedobject such as a vehicle, a watch, a key fob, a ring, a key card, atoken, a poker chip, a souvenir, a necklace amulet, and so forth. Acomputing device may be embedded in substantially any type of object.The mobile computing device can be a device that is user owned, rented,leased, associated with, or otherwise in the possession of the user. Auser owned device can include mobile computing devices that are actuallyowned by relatives, friends, and employers of the user.

The MMMIC device 201 incorporated in the mobile computing device 202 canbe used to communicate with other NFMI devices 204. For example, theNFMI devices may pass audio to and from a wireless headset configured tocommunicate using NFMI, exchange data to and from a computer, work as apassive keyless entry for an automobile or electronic security entrancelock, or may be configured to deliver advertisements at a commercialretail store such as a grocery store, department store, mall or othertype of retail outlet. In addition, NFMI devices may be used to exchangeinformation based on proximity with another person, such as socialnetworking information or peer to peer data exchange information. AMMMIC device used to deliver advertisements is referred to herein as aMMMIC solicitation device. The MMMIC device 201 contained in the mobilecomputing device 202 can also be configured to communicate with NFCcompliant devices, such as an NFC compliant point of sale (POS) terminal208 or other type of NFC compliant device.

In one example description, a user can set up his or her mobilecomputing device 202 to receive desired advertisements such as discountinformation on selected products when visiting a retail outlet, such asa grocery store. A MMMIC device operating in the mobile computing devicemay receive the advertisements from an NFMI solicitation device or anNFC compliant device. As the user navigates through the retail outlet,when he or she passes an NFMI solicitation device, a signal can be sentidentifying the product that is solicited. The MMMIC device operating inthe mobile computing device can receive the signal and can notify theuser through auditory, visual, or mechanical means activated in themobile computing device, such as a chime, an image, or a vibration. Ifthe product advertised by the NFMI solicitation device is a product thatthe user is interested in, as the user may have confirmed by configuringthe mobile computing device to receive such information, then the usercan be notified via his or her mobile computing device based on theinformation received by the MMMIC device 201 that is incorporated intothe mobile computing device 202.

In one example, the NFMI device 204 may display an image or descriptionof the product or service and provide a user interface (i.e. a keypad ortouch screen) to allow the user to select or choose to select theadvertised product/promotional information or coupon. Upon confirmation,the coupon may be transferred or transmitted to the user's mobilecomputing device without the need of the user to remove the device fromhis/her pocket or purse. This is very convenient and beneficial for theuser and the advertiser.

It can be very ineffective to require a user with an NFC enabled deviceto hold the device within the required 10 cm radius of an NFCtransmitter in the hope that this product actually has a couponavailable. In addition, it is ineffective advertising as the user mustmake the effort, versus the product (transmit device) activelysoliciting the user when the user is in proximity—such as walking downthe aisle. The user may not have intended to stop at this productotherwise. When a longer range device, such as the MMMIC device 201 isused, then the transceiver in the NFMI device 204 can sense the presenceof the MMMIC device 201, send its information, which can be received bythe MMMIC device. The mobile computing device 202 can then filter theinformation received to see if such solicitation is welcome or allowed.Upon passing the appropriate filters, the mobile computing device 202can alert the user via an audible sound or vibration, and communicateback to the NFMI device 204 to complete the exchange with the mobilecomputing device.

An NFMI device, such as the MMMIC device 201 is typically capable ofreceiving a signal that was transmitted within a distance of thereceiver that is approximately equal to a wavelength of the carriersignal divided by 2 pi (λ/2π). The region that is within this distanceis typically referred to as the near field region. When the carriersignal frequency of the NFMI devices is 13.56 MHz, then the maximumeffective distance for near field communication is approximately 3.4meters. A more efficient distance to receive the near field signal maybe within 2 meters (6 feet). Thus, when the user passes within 6 feet ofa desired product, the user can be notified through his or her mobilecomputing device that the product is near. Additional information, suchas a coupon, may be displayed on the user's mobile computing device toincentivize the user to purchase the product. The user can then locatethe product on the shelf and determine whether or not to purchase theproduct.

The user's mobile computing device 202 containing the MMMIC device 201can also be configured to detect the position of the NFMI solicitationdevice 204, thereby assisting the user to locate the desired product onthe store shelves. The use of an NFMI device to detect the position ofanother NFMI device on store shelves is more fully disclosed in U.S.Pat. No. 7,532,901, which is herein incorporated by reference.

The user can continue through the store to purchase other desiredproducts. When the user approaches the checkout stand, the user's mobilecomputing device 202 containing an MMMIC device 201 can be configured todetect an NFC compliant point of sale (POS) terminal 208 at the checkoutstand. The NFC compliant POS terminal may be configured to transmit asignal at 13.85 MHz. As previously discussed, this signal is intendedfor other NFC compliant devices and is not typically detectable by NFCcompliant devices at a distance of greater than CPC perimeter of 10 cm.

However, the MMMIC device 201 may be configured to detect the signalfrom the NFC compliant device at a distance up to and over one or twometers. When the user's mobile computing device 202 containing an NFMIdevice 201 detects a signal from an NFC compliant POS device 208, themobile computing device can query the user to determine if the userwants to switch the MMMIC device to an NFC compliant mode. By switchingthe MMMIC device to an NFC compliant mode, the security level can beincreased by reducing the size of the communication “bubble” in which atransmitted near field signal is detectable.

While the MMMIC device 201 can detect the low power signal transmittedby the NFC compliant POS device 208 at a distance greater than 10 cm,the opposite may not be true. The signal transmitted by the MMMIC devicemay have to be higher power than a typical NFC compliant transmittedsignal in order for the NFC compliant POS device to receive the signaltransmitted by the MMMIC device. Thus, security can be increased byswitching the MMMIC device 201 in the mobile computing device 202 to bein an NFC compliant state for a selected transaction. In a specificexample, the MMMIC device may change to NFC mode or an NFC compliantstate. When the MMMIC device is in an NFC mode or an NFC compliantstate, the MMMIC device may not be able to detect an NFC signal outsideof an NFC range (i.e. CPC perimeter), such as at a distance greater than10 cm from an NFC transmitting device. In one embodiment, the MMMICdevice may be configured to be in an NFC mode or NFC compliant statewhen the MMMIC device is brought within the CPC perimeter. However, theMMMIC device can also be in an NFC mode or NFC compliant state outsideof the CPC perimeter as well.

When the MMMIC device 201 is in an NFC compliant state then the MMMICdevice can be configured to transmit and receive signals based on theISO 14443 specification, thereby reducing the signal detection boundaryfor other NFC compliant devices to a radius of approximately 10 cm. Theuser can then transmit information, such as credit card information orother types of financial information that enables the retailer to obtainelectronic funding for the user's purchase. The information may beinformation such as credit card information to conduct an electronictransaction using his or her mobile computing device.

Communication between the mobile computing device 202 and the NFCcompliant POS Terminal 208 using the MMMIC device 204 can enablerelatively secure transactions to be conducted in a more convenientmanner. The data transfer rate of an NFC compliant device can besufficiently slow that it may take several seconds or longer for an NFCcompliant device to communicate selected information with the NFCcompliant POS terminal. If a user moves his or her NFC compliant devicefurther than 10 cm from the POS terminal while data is stilltransferring, it can disrupt the communication and may result in afailed financial or sales transaction. However, holding the devicewithin the 10 cm range for several seconds may be difficult for a user.

In one embodiment of the present invention, the MMMIC device 201 cancommunicate with the NFC compliant POS terminal in an NFC compliant modefor a duration necessary to transmit secure information, such as acredit card number, a personal identification number, an encryption key,a checking or savings account number, or other personal information.Once the secure information has been transmitted, the MMMIC device 201can be configured to switch to an extended mode in which the MMMICdevice can communicate with the NFC compliant NFC terminal at a distancegreater than 10 cm. Thus, a user may effectively “swipe” or “wave” hisor her mobile computing device past the POS terminal, providing asufficient length of time within the 10 cm range for the devices tocommunicate desired secure information. The user can then place themobile computing device back in his or her pocket or purse, whileinformation continues to be communicated between the devices. Forinstance, a sales receipt, an advertisement, a coupon, or otherinformation may be communicated from the POS terminal to the MMMICdevice so long as the user is within a selected distance, such as withinapproximately two meters of the POS terminal.

Thus, the MMMIC device can be used to provide a convenient means for auser to conduct relatively secure financial transactions and enable arelatively large amount of data to be communicated from the POS terminalwithout requiring the user to stay within 10 cm of the POS terminalthroughout the transaction. While this example is provided with respectto communication between the MMMIC device and a POS terminal, theconcept is not limited to a POS terminal. The MMMIC device can beconfigured to communicate secure communication via a low power mode,such as an NFC compliant mode, and then automatically switch to anextended mode to allow communication of non-secure data to occur over anextended range, such as within 2 meters of another NFC compliant or NFMIdevice.

In one embodiment, the MMMIC device 201 can communicate simultaneouslyin both NFC compliant mode and NFMI mode (i.e. non-NFC compliant mode).For instance, the MMMIC device 201 in the mobile computing device maycommunicate with an NFMI device 204 while also conducting NFC compliantcommunication with the NFC compliant POS Terminal 208.

When the MMMIC device 201 is placed in an NFC compliant mode, it must bedetermined which antenna 104-108 (FIG. 1) to use in the MMMIC device toconduct the NFC compliant communication. In one embodiment, anon-optimal antenna can be used, thereby freeing up the optimal antennato conduct communication with another NFMI device, such as a headphoneor ear piece.

For instance, the user may be using the MMMIC device 201 to transmit thevoice signal of a phone call from the user's mobile computing device toan earpiece worn by the user (not shown) while the user is paying foritems at a POS device. In one embodiment, the antenna with the best(most optimal) selection metric can always be used to transmit the voicecommunication to the ear piece. One of the remaining antennas in theMMMIC device can be used to transmit and receive signals to the NFCcompliant POS terminal 208 when the MMMIC device 201 is placed in an NFCcompliant mode to conduct the financial transaction with the POSterminal.

In one embodiment, the plurality of antennas in the MMMIC device can beranked based on the selection metric measured for each antenna. Sincethe need to guarantee proper alignment and/or polarization between twoNFC compliant devices is significantly reduced, due to the closeproximity of the devices when communication occurs (typically less than4 inches or 10 cm), then the antenna with the lowest rank in the NFMIlink may be assigned to communicate with the NFC compliant device whenthe MMMIC device is placed in an NFC compliant mode with a selected NFCcompliant device. Alternatively, any antenna other than the top rankedantenna (used for NFMI communication) may be used to communicate withthe NFC complaint device.

In another embodiment, the user may determine that the additionalprivacy provided by the reduced circumference or link distance is notneeded. In this case, the user may be able to conduct the transactionwithin a distance of about λ/2π (3.5 meters at a frequency of 13.56 MHz)from the NFC compliant POS terminal 208, as previously discussed. Inaddition, the data transmitted and received by the MMMIC device 201 canbe scrambled and/or encrypted, thereby making it difficult to intercept.

In one embodiment, the user may use his or her mobile computing device202 to establish predetermined limits, such as financial limits, inwhich the NFMI enabled mobile computing device can be used to conduct afinancial transaction at the greater distance (i.e. when it is not inNFC compliant mode).

For example, the user may determine that for purchases for productscosting less than $20.00 then the financial transaction between theMMMIC enabled mobile computing device 202 and the NFC compliant POSterminal 208 can be conducted at a distance beyond the CPC perimeter ofup to 3 meters from the terminal 208. The user will typically enterinformation, such as a pass code, at the POS terminal to complete thepurchase. However, this may not be necessary in all situations. Forinexpensive purchases, the user may simply pass within the determineddistance of the NFC compliant POS terminal and receive a notification,such as a chime, that the purchase was completed. For instance, at alibrary the user can pass the checkout stand, hear a chime, and knowthat all of the books the user has selected are checked out to the user.The NFC compliant POS terminal can display information related to thepurchase, rental, lease, or other type of transaction. For example, thePOS terminal can display information such as what was purchased and theamount, and provide a receipt if desired.

In another example, the user may have previously established a customeror user account and the secure information is stored on the ServiceProvider's database. Such secure information will not be transmittedover the extended near field link. Only the customer account number orID information (not credit card or financial info) is exchanged andtherefore vulnerable.

This (potentially exposed or vulnerable) information would not be ofworth as it is not usable at other locations or institutions—and can bemore closely controlled. For instance, the information may be controlledthrough the use of a photo that may be displayed to a POS attendant. Thetransaction amount may have limitations. The account may have a maximumactivity level, such as one transaction per day, and so forth.

When the NFMI device 201 is configured to operate at two separatefrequencies, such as 13.92 MHz with other NFMI devices and 13.56 MHz or13.85 MHz with NFC compliant devices, a separate RF front end may beused to detect and demodulate the NFMI signal and the NFC compliantsignal. The NFMI device can be configured to route transmitted orreceived signals to the appropriate front end through detection,filtering, and switching. Each front end can include the appropriatematching filters, band pass filters, low noise amplifier, and downconverter for the selected frequency. When the same operating frequencyis used by both types of devices then the NFMI device may use a singlefront end to receive both NFC compliant signals and non-compliantsignals from other NFMI devices. A different modulator or demodulatormay be used depending on the type of modulation scheme used by eachdevice.

In another embodiment, FIG. 3 depicts a flow chart for a method 300 forclose proximity communication. The method comprises detecting 310 asignal transmitted by a close proximity communication (CPC) device atone of a distance of greater than the CPC perimeter, or less than a CPCperimeter, with a multi-mode magnetic induction communication (MMMIC)device with at least one antenna. It should be noted that, while theMMMIC device can detect the signal outside of the CPC perimeter, theMMMIC device can also detect an NFC device within the CPC perimeter. Thetype of device transmitting the detected signal is identified 320. TheMMMIC device is enabled 330 to communicate with the CPC device at one ofthe distance of greater than the CPC perimeter and a distance of lessthan the CPC perimeter based on the type of device that is identified.In one embodiment, a magnetic induction diversity scheme for the MMMICdevice to communicate can be selected based on the distance over whichthe communication will occur with the identified device.

For instance, when it is determined that the type of NFC compliantdevice is a point of sale terminal, communication with the identifieddevice may be limited to a distance of less than 10 cm. A magneticinduction diversity scheme can be selected, such as selecting theantenna with the lowest selected measured metric to transmit and receivewith the NFC compliant device. When the identified device is an NFMIsolicitation device then it may be determined to communicate at adistance of over 10 cm. A magnetic induction diversity scheme can beselected, such as using two antennas with the best metrics to receivethe signal and summing the received signals together to maximize thedistance over which the communication can occur.

While a CPC perimeter distance of 10 cm is used in the example, theactual distance of the perimeter is device dependent. Different types ofclose proximity communication devices can have different CPC perimetersizes, as previously discussed. For instance, the CPC perimeter may be 5cm, 10 cm, 20 cm, 50 cm, or even 100 cm or more.

In another embodiment, a reconfigurable magnetic induction communicationsystem is disclosed. The system comprises a transceiver configured totransmit and receive an NFMI signal. A configuration module is incommunication with the transceiver. The configuration module can provideinstructions to a modulation module configured to select one of aplurality of modulation types. The selected modulation type can be usedto modulate and/or demodulate a transmitted or received NFMI signal. Theconfiguration module can also provide instructions to a diversity moduleconfigured to select at least one of a plurality of substantiallyorthogonal antennas coupled to the transceiver to transmit and receivethe NFMI signal.

In one embodiment, the modulation module can communicate with areconfigurable modulation chip. For instance, a Field Programmable GateArray (FPGA) chip may be reprogrammed to provide different types ofmodulation and demodulation, such as phase-shift keying, frequency-shiftkeying, amplitude-shift keying, quadrature amplitude modulation,minimum-shift keying, Gaussian minimum-shift keying, orthogonalfrequency-division multiplexing, or another desired type of modulationor demodulation. Alternatively, the modulation module can be used toswitch the transceiver between different types of modulation chips orcircuit boards. For instance, one chip can be configured to performamplitude-shift keying and another chip can be configured to performGaussian minimum-shift keying. The modulation module can switch aconnection with the transceiver to the correct chip to conduct thedesired type of modulation. The type of modulation can be selected tocommunicate with another magnetic induction communication system using aselected type of modulation.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

What is claimed is:
 1. A reconfigurable magnetic induction communicationsystem comprising: a transceiver configured to transmit and receive anNear Field Magnetic Induction signal; a configuration module incommunication with the transceiver; a modulation module configured toselect one of a plurality of modulation types to at least one ofmodulate and demodulate the NFMI signal based on instructions from theconfiguration module; and a diversity module configured to select atleast one of a plurality of substantially orthogonal antennas coupled tothe transceiver to transmit and receive the NFMI signal based oninstructions from the configuration module, wherein the diversity moduleis configured to compare a selection metric of the received signal foreach of the plurality of orthogonal antennas and transmit the NFMIsignal on at least one of the plurality of orthogonal antennas having aselection metric.
 2. The system of claim 1, wherein the modulationmodule is configured to select one of the plurality of modulation typesselected from the group consisting of phase-shift keying,frequency-shift keying, amplitude-shift keying, quadrature amplitudemodulation, minimum-shift keying, Gaussian minimum-shift keying, andorthogonal frequency-division multiplexing.
 3. The system of claim 1,wherein the modulation module is configured to switch from a firstmodulation circuit to a second modulation circuit.
 4. The system ofclaim 1, wherein the modulation module is configured to communicate witha reconfigurable modulation chip to instruct the modulation chip toproduce one of a selected type of modulation and demodulation.
 5. Thesystem of claim 1, wherein the diversity module is configured to selectone of the plurality of orthogonal antennas to communicate with a closeproximity communication device at a distance of less than about 10centimeters, wherein the antenna selected is a most inefficient antennaof the at least two antennas.
 6. The system of claim 1, wherein thediversity module is configured to select one of the plurality oforthogonal antennas to communicate with a close proximity communicationdevice at a distance of less than about 10 centimeters, where theantenna selected is not a most efficient antenna of the at least twoantennas.
 7. The system of claim 1, further comprising enabling thereconfigurable magnetic induction communication system to communicatewith a close proximity communication device using at least one antennaselected from the plurality of orthogonal antennas based on the type ofdevice that is identified.
 8. The system of claim 1, wherein thediversity module is configured to select one of the at least twoantennas to communicate with a close proximity communication device at adistance of less than about 10 centimeters while simultaneouslycommunicating with at least one other near field magnetic inductive(NFMI) communication device using another of the at least two antennas.9. The system of claim 8, wherein the at least one other NFMIcommunication device is positioned at a distance from the transceiver ofless than 10 centimeters.
 10. The system of claim 8, wherein the atleast one other NFMI communication device is positioned at a distancefrom the transceiver of greater than 10 centimeters.
 11. The system ofclaim 1, wherein the diversity module is configured to select aplurality of the at least two antennas to receive an NTMI signal and sumthe signal received from the plurality of antennas.
 12. The system ofclaim 1, wherein the diversity module is configured to compare aselection metric of the received signal for each of the plurality ofantennas and receive the NFMI signal on at least one of the plurality oforthogonal antennas having a desired selection metric.
 13. Areconfigurable magnetic induction communication system comprising: atransceiver configured to transmit and a Near Field Magnetic Inductionsignal; a configuration module in communication with the transceiver; amodulation module configured to select one of a plurality of modulationtypes to at least one of modulate and demodulate the NFMI signal basedon instructions from the configuration module; and a diversity moduleconfigured to select at least one of a plurality of substantiallyorthogonal antennas coupled to the transceiver to transmit and receivethe NFMI signal based on instructions from the configuration module,wherein the diversity module is configured to compare a selection metricof the received signal for each of the plurality of antennas and receivethe NFMI signal on at least one of the plurality of orthogonal antennashaving a desired selection metric.
 14. The system of claim 13, whereinthe diversity module is configured to compare a selection metric of thereceived signal for each of the plurality of orthogonal antennas andtransmit the NFMI signal on at least one of the plurality of orthogonalantennas having a desired selection metric.
 15. The system of claim 13,wherein the modulation module is configured to select one of theplurality of modulation types selected from the group consisting ofphase-shift keying, frequency-shift keying, amplitude-shift keying,quadrature amplitude modulation, minimum-shift keying, Gaussianminimum-shift keying, and orthogonal frequency-division multiplexing.16. The system of claim 13, wherein the modulation module is configuredto switch from a first modulation circuit to a second modulationcircuit.
 17. The system of claim 13, wherein the modulation module isconfigured to communicate with a reconfigurable modulation chip toinstruct the modulation chip to produce one of a selected type ofmodulation and demodulation.
 18. The system of claim 13, wherein thediversity module is configured to select one of the plurality oforthogonal antennas to communicate with a close proximity communicationdevice at a distance of less than about 10 centimeters, wherein theantenna selected is a most inefficient antenna of the at least twoantennas.
 19. The system of claim 13, wherein the diversity module isconfigured to select one of the plurality of orthogonal antennas tocommunicate with a close proximity communication device at a distance ofless than about 10 centimeters, where the antenna selected is not a mostefficient antenna of the at least two antennas.
 20. The system of claim13, further comprising enabling the reconfigurable magnetic inductioncommunication system to communicate with a close proximity communicationdevice using at least one antenna selected from the plurality oforthogonal antennas based on the type of device that is identified. 21.The system of claim 13, wherein the diversity module is configured toselect one of the at least two antennas to communicate with a closeproximity communication device at a distance of less than about 10centimeters while simultaneously communication with at least one othernear field magnetic inductive (NFMI) communication device using anotherof the at least two antennas.
 22. The system of claim 21, wherein the atleast one other NFMI communication device is positioned at a distancefrom the transceiver of less than 10 centimeters.
 23. The system ofclaim 21, wherein the at least one other NFMI communication device ispositioned at a distance from the transceiver of greater than 10centimeters.
 24. The system of claim 13, wherein the diversity module isconfigured to select a plurality of the at least two antennas to receivean NFMI signal and sum the signal received from the plurality ofantennas.